1.Joint Optimization of Savitzky-Golay Smoothing Models and Partial Least Squares Factors for Near-infrared Spectroscopic Analysis of Serum Glucose
Jun XIE ; Tao PAN ; Jiemei CHEN ; Huazhou CHEN ; Xiaohuan REN
Chinese Journal of Analytical Chemistry 2010;38(3):342-346
The optimal model for the near-infrared spectroscopic analysis of serum glucose was established by partial least squares(PLS) and Savitzky-Golay(SG) smoothing method. Based on the prediction effect of the optimal single wave number model, a new dividing method for calibration set and prediction set was given. The calibration and prediction models were established by PLS method adopting the combination bands of 10000-5300 cm~(-1) and 4920-4160 cm~(-1) with Savitizky-Golay(SG) smoothing. By extending the number of smoothing points to 5, 7, ..., 87(odd) and polynomial degree to 2, 3, 4, 5, 6, fourteen smooth coefficient tables including 582 smooth modes were calculated. All PLS models corresponding to all smooth modes and all PLS factors(1-40) were constructed. The optimal model was selected by the prediction effect. And the derivation order was 1, the polynomial degree was 3 or 4, the number of smoothing points was 53, the optimal factor was 7 and the optimal RMSEP reach 0.376 mmol/L. The dividing method for calibration set and prediction set, the extending of SG smoothing modes, large-scale optimization combining SG smoothing modes and PLS factors can be effectively applied for the model optimization of near-infrared spectroscopic analysis.
2. Development and application of real-time qPCR assay for detecting Sendai virus gene copy number
Xiaohuan ZHANG ; Wenhao SU ; Xiuxiu REN ; Tingting ZHAO ; Yinan WANG ; Jiangbo WEI
Chinese Journal of Experimental and Clinical Virology 2019;33(6):637-640
Objective:
To develop a real-time quantitative PCR (qPCR) assay for detecting Sendai virus gene copy number.
Methods:
The recombinant plasmid was constructed and a reference used to establish the real-time qPCR method with the TaqMan probe and verified for reproducibility and sensitivity.
Results:
The linear range of the developed real-time qPCR assay was 1.024 × 103 ~5 × 1010 copies/μl, with an R2 value of more than 0. 99. The standard recovery of the tested samples was 84.56%~119.48%.
Conclusions
Compared with traditional hernagglutination assay for particle number detection, this method has higher sensitivity, better repeatability and high quantitative accuracy. It can be used for the detection of particle number of vaccine with sendai virus as the carrier, so as to detect the specific activity of vaccine products.
3.Construction of recombinant herpes simplex virus 2 expressing enhanced green fluorescent protein using CRISPR/Cas9
Wenhao SU ; Xiuxiu REN ; Tingting ZHAO ; Yinan WANG ; Shishi LI ; Qiufang HUANG ; Xiaojie WANG ; Xiaohuan ZHANG ; Jiangbo WEI
Chinese Journal of Microbiology and Immunology 2022;42(5):369-375
Objective:To construct a recombinant herpes simplex virus 2 (HSV-2) expressing enhanced green fluorescent protein (EGFP) using clustered, regularly interspaced, short palindromic repeat/CRISPR-associated nuclease 9 (CRISPR/Cas9) technology.Methods:Four strategies for inserting exogenous EGFP gene into HSV-2 genome using CRISPR/Cas9 technology were designed: (1) conventional homology-directed repair: circular two homology arm donor-mediated gene knock-in; (2) linearized single homology arm donor-mediated gene knock-in; (3) homology-independent targeted integration; (4) conventional homology-directed repair-mediated by cell lines stably expressing Cas9 and sgRNA.Results:The recombinant virus HSV-2-EGFP was successfully constructed based on the second, the third and the fourth strategies. The second strategy was the most efficient, followed by the third and the fourth strategies. The purified recombinant virus could stably express green fluorescent protein in seven passages and shared similar growth characteristics in Vero cells to the parental virus.Conclusions:Linearized single homology arm donor could increase the efficiency of gene knock-in, and cell lines stably expressing Cas9 and sgRNA could increase the efficiency of gene knock-in mediated by homology-directed repair.
4.Effects of genomic location of foreign gene in measles virus vector on gene expression and virus replication
Wenhao SU ; Xiuxiu REN ; Tingting ZHAO ; Yinan WANG ; Shishi LI ; Qiufang HUANG ; Xiaojie WANG ; Xiaohuan ZHANG ; Jiangbo WEI
Chinese Journal of Microbiology and Immunology 2022;42(12):924-930
Objective:To investigate the effects of genomic location of a foreign gene in Shanghai-191 strain measles virus (MV) vector on gene expression and virus replication.Methods:The nucleotide sequence encoding S1 protein of SARS-CoV-2 was inserted at different positions in MV antigenome (the upstream of the N gene, between P and M genes, between H and L genes), and co-transfected into 293T cells with helper plasmids coding T7 RNA polymerase and N, P, and L proteins, respectively. The transfected cells were lysed and the supernatants were used to infected Vero cells to harvest recombinant viruses. S1 proteins expressed by the recombinant viruses were identified by RT-PCR, indirect immunofluorescence assay, Western blot and ELISA. Growth kinetics of the recombinant viruses were analyzed.Results:Recombinant viruses were failed to be rescued when the S1 protein-coding sequence was cloned into the upstream of N gene. Two recombinant viruses, MV-M-S1 and MV-L-S1, were successfully rescued when cloning the S1 protein-coding sequence into the intergenic region between P and M genes, or H and L genes, and could express S1 protein. MV-M-S1 expressed more S1 protein than MV-L-S1, but the titer of MV-M-S1 was lower.Conclusions:Inserting a foreign gene at different positions in the MV genome might have different effects on gene expression and virus replication. This study provided reference for the subsequent construction of MV vector.